These fish are often kept by aquarists as they are dutiful algae-eaters and smaller in adult size than the common plecos usually seen in petshops. Size is up to 15 cm (male), 12 cm (female), recommended temperature 23-27 degrees Celsius, lifespan up to 12 years. They are hardy animals, tolerant to a wide range of water conditions, breeding easily in captivity, compatible with most other freshwater fish, though typically mottled brown in colour, other species are more exotic - spots of bright yellow on a dark background being a common patternation, albino variants are also common. It is thought that the eggs of the bristle-nosed pleco are light sensitive, albino fish may be the result of exposure to excesive light.
Historically commonly available species of Ancistrus were Ancistrus dolichopterus
and Ancistrus temminckii
, other species are now available though exact identification is difficult.
Feeding is easy, bristlenoses will graze on algae and other surface growing organisms as well as eating algae wafers or tablets, flake food, squash, spinach, cucumber, zucchini, green beans and peas however they have been known to accept frozen bloodworms as part of their diet. Aquarium specimens may starve for lack of algae or other plant matter; algae wafers or other low-protein foods are recommended. Keepers should watch for the abdomen to take on a sunken appearance, indicating insufficient nutrition.
Like other plecs benefit from the addition of bogwood
, which they will rasp at and use as a hiding place - in the absence of other plant matter (sources of fibre) wood may be essential to the survival of these fish in the aquarium as it helps digestion of typically high protein fish food.
Sexing is very easy as the female will occasionally have bristles around the edge of the chin and the male will have them up the center of the head
Breeding is also possible: Males attract females to small cave or hollow, then guard eggs after fertilization through hatching (4-8 days) until fry are free swimming (4-6 days after hatching); the aquarist need only supply a suitable cave, food, and one of each sex.
Caution should be taken with the spines (odontodes) - although the risk of personal injury is small with this genus the hooked nature of the odontodes means that a bristlenose may become trapped in non-natural material such as sponge filters and netting.